Ash and mud

A huge amount of loose ash and mud debris has been deposited on
the flanks of the volcano. Much of the remaining vegetation is killed
by the effects of ash. When there is heavy rainfall, this debris
gets washed down the main valleys giving rise to mudflows (sometimes known as lahars). This hazard
will continue until vegetation becomes re-established.

Ash is made of fine particles of volcanic rock and can be produced
by three main processes (illustrated below): phreatic eruptions (caused by magma heating groundwater); explosions and pyroclastic flows.

Phreatic eruptions , October 1995.

Explosions, March 1999.

Pyroclastic flows, June 1997.

Most of the ash on Montserrat has been blown to the west over Plymouth.
Ash kills vegetation, can be a hazard to human and animal health
and causes roofs to collapse.

'No play today'; Golf Course, February 1998.

Mudflows at Bramble airport, December 1998.

Old Road Bay and the Golf Course, April 2000.

The clock tower and all of central Plymouth is being buried by mud transported down Fort Ghaut. Photo taken April 2000.

Ash can be a major hazard to structures as shown by the collapsed roof of Radio Antilles, Plymouth.